Accession Number : ADD012556

Title :   Harmonic Distortion Reduction Technique for Data Acquisition.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Evans,William P

Report Date : 16 Sep 1986

Pagination or Media Count : 6

Abstract : An analog to digital converter (ADC) is presented which uses a calibration technique to reduce harmonic distortion in data acquisition systems. This mechanization also allows faster conversion rates than previously possible for high resolution analog-to-digital converters. This converter makes use of a subrange or half Flash architecture where the subrange digital-to-analog converter (DAC) is augmented with a software calibrated DAC which removes system nonlinearities. The advantage of this system is that it allows the building of higher speed data acquisition systems with higher spurious free dynamic range than would be possible with conventional techniques. By adding the correction to the input of the subrange ADC, correction resolution can be a fraction of a quanta. A second approach using the same mathematics places at the output of the ADC a RAM or ROM look up table which linearizes the transfer function.

Descriptors :   *PATENTS, *ANALOG TO DIGITAL CONVERTERS, *DIGITAL TO ANALOG CONVERTERS, *PROCESSING EQUIPMENT, *DATA ACQUISITION, HARMONIC GENERATORS, SUPPRESSORS, ARCHITECTURE, CALIBRATION, COMPUTER PROGRAMS, CONVERSION, CORRECTIONS, DISTORTION, FLASHES, HARMONICS, TRANSFER FUNCTIONS, RESOLUTION, REDUCTION, MULTIPLEXING, MATHEMATICS, METHODOLOGY, MECHANIZATION, RATES, HIGH RESOLUTION, NONLINEAR SYSTEMS

Subject Categories : Electrical and Electronic Equipment
      Computer Programming and Software
      Computer Hardware

Distribution Statement : APPROVED FOR PUBLIC RELEASE